Malicious PDF — malware analysis report

Static analysis result for SHA-256 0339ebfad7bc73aa…

MALICIOUS

PDF

8.5 KB
MD5: 9706bf734391bc6757aa197e0465d9b4 SHA-1: c688880c4bf062b73bf67b3a908b930a28a4519a SHA-256: 0339ebfad7bc73aa7b5d985e052301c51049ab5a90dc19153ea949fb0014e5ce
266 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file contains embedded JavaScript that exploits CVE-2007-5659 in Adobe Reader. The script is designed to download a second-stage payload from the URL http://redkoeebalovo.us/cgi-bin/php/z002106203r0409R0644596cXb937571cY7b836d92Z0100f060. The JavaScript uses String.fromCharCode and decodes hex-encoded strings to construct the final payload URL and execute it.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 10

  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • Adobe Reader APSB08-13 patch-range version gate (CVE-2007-5659) high CVE likely PDF_JS_ADOBE_APSB08_13_PATCH_GATE
    PDF JavaScript gates the exploit payload on (>= 8 && < 8.1.1) OR (< 7.1) — the Reader 7.0.x / 8.0–8.1.1 window patched by Adobe APSB08-13 for the CVE-2007-5659 Collab.collectEmailInfo buffer overflow. Only kits that target that exact bug check both of those patch points; benign scripts do not.
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • PDF JavaScript shellcode contains an embedded download URL high PDF_JS_SHELLCODE_DOWNLOAD_URL
    Decoded PDF JavaScript shellcode contains a hardcoded http(s) URL stored as little-endian %uXXXX Unicode escapes. Reader exploit shellcode embeds the second-stage fetch URL this way and pulls it down with a urlmon/URLDownloadToFile-style download-and-execute (commodity downloader behaviour rather than a specific Acrobat CVE).
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • syncAnnotScan annotation-staging primitive low PDF_FOXIT_SYNCANNOTSCAN
    PDF JavaScript calls syncAnnotScan() — a no-op annotation-enumeration primitive used by exploit-kit JavaScript to stage payload reads from annotation /Subject fields before eval(). Not a vulnerable sink itself; rarely seen in legitimate PDFs. (identified after JavaScript deobfuscation)
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://redkoeebalovo.us/cgi-bin/php/z002106203r0409R0644596cXb937571cY7b836d92Z0100f060

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0004_000.js
8b70e431ed36d84945464549cd8184fb5a7cf6ee13d19263f40a1485872c8893
pdf-javascript-stream PDF /JS object 4 at offset 0xE1 2105 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
numeric_charcode_stage_000.js
9d5c7e01faed5b04e9ec11f1d98b73f0012c871beaf60e9f9d32ad6df00d46f7
deobfuscated-js numeric char-code string decoded JavaScript at offset 0xEF 550 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
a5dc07a7af710e98d66865d614b81a1d9acb2e798de980de1d4a435943fd8b34
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1C9B 1828 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
df0bd4434f29619bae2cfef9221c44a1f0bb3f5b53dbb5b05f5edd2738b870c9
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x4D0 5103 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).